BGA Improvements
Support virtual width/height, and x/y offset, to allow double buffering and such. Read the resolution registers to see if the change took effect (is the device disabled during change?) (the check must be done before reenabling). Only the X resolution needs to be divisible by 8 on bochs/qemu, no limit on virtualbox. Investigate whether any VMs support more finegrained offset of the framebuffer within video memory. Add a manual page and installation(7) documentation on how to enable in bochs/qemu/virtualbox.